In recent years, fiber optic cables have replaced traditional copper wire as the preferred medium for telecommunications. As with traditional wires, it is often necessary to secure strips of optical fiber in specific configurations or position strips of optical fiber in predetermined relationships relative to mounting or supporting surfaces. For example, as with copper wires, it is often necessary to provide interconnections and cross-connections between optical fibers at various locations in the distribution system.
The prior art is replete with fiber optic junction boxes, organizers or the like designed for this purpose. Several of these structures utilize fiber-organizing trays that slide out of a housing or cabinet-like drawer. In some units, the trays are pivotally attached to the housing.
Common features of a conventional fiber-organizing tray include a spool or reel for storing excess fiber slack and maintaining a minimum bend radius in the fiber to prevent undue stress or kinks. Conventional fiber organizing trays typically also include a splice area having retaining clips, adhesives or other means for attaching splice elements to the trays and tabs or lugs which keeps the fibers from slipping off the reel or out of the tray. A cover is often provided for protecting selected portions of the fibers.
While the prior art trays are useful in providing a structure that allows for organizing of the optical fiber strips at various locations in the distribution system, they nevertheless suffer from numerous major drawbacks. Some of these drawbacks are related to the retaining clips and the tabs or lugs that are used for keeping the strips of optical fiber in proper alignment and, in particular, that are used for preventing the strips of optical fiber from slipping off the reels or out of the trays.
One of the common drawbacks associated with conventional fiber tray retaining structures is that the tabs or lugs, sometimes because of manufacturing considerations, are often mounted relatively close to a side or front wall of the tray. Portions of the optical fiber adjacent the walls of the tray therefore often undergo bending beyond their minimum bend radius. As is well known in the art, bending of a strip of optical fiber beyond the minimum bend radius of the fiber potentially induces optical losses in the fibers and/or promotes fractures in the latter.
In order to circumvent the disadvantages associated with tabs or lugs located close to the walls of the tray, fiber-retaining clips positionable away from the walls are sometimes used. However, most prior art fiber optic retaining clips also suffer from major disadvantages. The design of some prior fiber optic retaining clips seems to be derived without suitable adaptation from the design of prior art clips typically associated with copper wires or cords such as the retaining clips disclosed in the following documents:                U.S. Des. Pat. No. 329,588 naming Richard E. MICHEL Jr. as inventor and issued Sep. 22, 1992;        U.S. Des. Pat. No. 293,205 naming Yoshihito NAKANO as inventor and issued Dec. 15, 1987;        U.S. Des. Pat. No. 428,330 naming Dare T. JOHNSTON et al as inventors and issued Jul. 18, 2000; and        U.S. Des. Pat. No. 366,606 naming Toshinobu NAKAMURA as inventor and issued Jan. 13, 1996.        
Most of the prior art retaining clips disclosed in the above-cited documents require that the fiber be twisted, bent or otherwise forced into the retaining structure formed by the clip thus creating undue localized stresses in the fiber. These undue stresses, in turn, potentially cause a loss of optical and mechanical properties.
Other clip designs such as that exemplified by U.S. Des. Pat. No. 329,588, allow for insertion of the optical fiber into the retaining structure without creating undue stresses on the fiber but suffer from the fact that the fiber may easily be unwantingly removed from the retaining structure formed by the clip through its insertion slot.
The risks of having the strips of optical fiber unwantingly slide out of the retaining structures through their insertion slot is compounded by the fact that optical fibers have an inherent resiliency which tends to bias the fibers towards a generally rectilinear configuration. Hence, when a bundle of optical fiber is retained in a clip such as that exemplified by U.S. Des. Pat. No. 329,588, the inherent resiliency of the fiber greatly increases the risks of having at least one of the fiber strips slip out of the insertion slot.
Yet another drawback associated with conventional fiber tray clips, tabs or lugs relates to the fact that these prior art retaining structures often present relatively sharp edges. During manipulation of the strips of fiber adjacent to these retaining structures or during storage of the strips of fiber in the trays, the strips of optical fiber that come into contact with the relatively sharp edges may be subjected to local pressures. The local pressures may, in turn, create local stresses again potentially altering the optical and/or mechanical properties of the fibers. Accordingly, there exists a need for an improved optical fiber retaining clip.